water injection?

[Guest bluex_v1]

Well I'm just throwing this out there out of curiousity and so I can maybe understand things a little better:

I've heard of water injection used in supercharged aviation powerplants, but how about the feasibility of a water injection system on a supercharged engine of somewhere around 10:1 static compression at sea level? I guess you would have to have a really stout bottom end, but could you fab something up using a nitrous system basically, except replace the nos bottle with an alcohol/water solution feeding into the plates with a high pressure fuel pump?

or would you pretty much get the same effect if you just sprayed it with nitrous and dropped the supercharger?

..sorry if this is silly, just struggling trying to learn about forced induction and detonation.

[Guest Anonymous]

Water injection is a great way to lower detonation and most passenger car applications are intended to allow the user to raise boost levels in turbo and s/c cars. Water is I think the best anti-detonant available and from what I have read it works. There are a few systems on the market, the bad part is having to fill the container all the time. Im not sure if compression is an issue though, I would venture to say it isnt, since its supposed to be on a forced-induction engine anyway.

[ZR8ED]

I've been thinking about posting about this very question..

 

I'm more interested why more people are not using it.. I found some good web sites with do it yourself instructions on how to build a system. I too have been toying with the idea, but at this point it is not neccessary for me.. my car will run out of fuel long before I have to worry about detonation and cranking the boost up more.

 

When blended with alcohol, it will give a bit of fuel to burn..(not much tho)

 

It is a cheap and easy method of increasing your boost levels without going through all kinds of extra work to the engine..

 

I know of guys in the past who have had dead simple turbo FI setups and got away with outragous amounts of boost by using water injection.

 

For the budget builder, it should be more common place. don't know why poeple don't talk about it more..

 

I've got almost everything I need to build a system.. not sure of benifits to me at present..

 

Anyone tried or is currently using water injection?.. or is this a kind of racer secret weapon..?

[SleeperZ]

It seems to me water/alcohol injection is a poor substitute for intercooling. The water/alcohol mixture possibly cannot increase the density of the air like an intercooler can (this is just me speculating..) It seems to me that reducing the cause of detonation by lowering the temperature is a more direct solution than displacing some of your air volume with stuff that just inhibits the burn.

[Guest Anonymous]

Personally I think its a band-ade. If the car is detonating, your either pushing it to much with the boost for your compression ratio, timing or using to cheap of a fuel. It will cool the combustion and deter detonation and with alcohol it surely would be cooler, but I agree better intercooling or just lowering the compression ratio to something that produces what you want without the ping is a much more stable solution. With the EFI computers we have now, its easy to roll off some timing to keep it from detonating (granted that limits power, but it also limits the dollars that will fly out of your wallet when you crush the ring lands and piston tops from detonation). Just an opinion, everyone has one and only yours will fit if you catch my drift.

 

Regards,

 

Lone

[Pop N Wood]

Once again showing my age, but water injection did gain some popularity back in the 70's to help high compression muscle cars cope with the lower octane gas. When the octane went away, most people backed off on the timing to avoid the detonation. Water injection allowed you to regain the correct ignition timing.

 

WWII airplanes used water-methonol injection, but once again, only under War Emergency Power. Those airplanes had all kinds of manual controls (like boost pressure, carb air/fuel ratio and even supercharger drive speed). The pilots could lean out the mixture and reduce the boost to maximize cruising range. Then when going into combat, go to full boost, turn on the water injection and engage the nitrous!

 

It is my understanding that water injection cools the intake air to prevent detonation (just like an intercooler or dry ice pack). I don't think the water itself does anything to inhibit combustion.

 

I would think water injection would work extremely well with a modern, knock sensor equipped car. If the water injection is on, the computer could advance the timing for max power. With no water injection, the knock sensor should automatically retard the timing (just like bad gas will).

 

I don't see anything wrong with water injection. But to get andvantage out of it you would have to retune your engine. Look at what Scotty does with his GNZ (if I am interpreting his posts correctly). Brew up some race gas and crank up the boost!

[BLKMGK]

Talk to some of the Buick guys - and now the Supra guys. I know a guy who is running STOCK injectors on his Supra and a T-78 single turbo with some pretty scary boost - and NOT detonating. He's making power too, this is no crutch. He's spraying a combo of alky and water and the datalogs show GOOD things. He'll probably be selling this kit when he's done. A Guy local to me is running it too on stock Supra electronics - NO knock retard on pump gas and near race gas levels of boost. Frankly, I'm finding most of the results I've dug up pretty convincing! http://www.aempower.com/bbs/viewtopic.php?t=715

 

http://www.aempower.com/bbs/viewtopic.php?t=552

 

Funny this has come up - I'm looking into it BIGTIME. The problem you guys will run into is controlling the darned stuff. In my case I can run a solenoid like an injector with my AEM (Aquamist has a solenoid) but I'm not sure how you guys would best do this. The guy I know is actually ramping his injectors DOWN some when the spray comes on. Plugs come out sparkling clean too BTW Combusion chambers get steam cleaned as a side bonus.

 

Some things I've learned - use a good nozzle - stainless if you run alky. Distilled water, put a filter in the system and a check valve too. Ford F150 framerail mounted fuel pump is supposed to make a good (compact) pump for this. It develops 95PSI. There's an Agri pump you can use too IF you don't run too much alky - it can ignite as the pump isn't rated for flammables. That one develops 65PSI but can be bumped up. The F150 pump is supposedly stainless inside, the Agri isn't. Oil burner companies make some decent nozzles but the Aquamist ones look goodbest to me. I ran across an adjustable Hobb's switch that might help you guys out but don't think I bookmarked it It was from an OEM app though.

 

Anyway, I've got some info on this and the testimonies I've read seem to say that this stuff works. It may not make quite as much power as "race gas" but it also doesn't cost damned near $4 agallon either! I cannot afford to run race gas 24X7 but if 100% max power is what you want by all means that's probably the best way to do it...

[Guest shuyun]

It was my understanding from the information I had that Water Boost is not the same as adding water to keep detonation away by displacing fuel/air mixture. With the super octane aviation fuel the plane ran and at atmospheric pressures lower than see level the water atomized (broke down to hydrogen and oxygen and added power!!!) just like the nitrous oxide adds extra hydrogen and oxygen to make more power. Its draw back was it increased the thermal output of combustion and could melt the pistons. I will talk to the Allison mechanic that goes to my church who worked on these systems and conform my facts.

[660Z]

Yenko made a 82 turboZ28 his solution...windshield washerfliud.. it`s cheap,it`s everywhere,it`s alcohol and water

[SleeperZ]

Originally posted by shuyun:

It was my understanding from the information I had that Water Boost is not the same as adding water to keep detonation away by displacing fuel/air mixture. With the super octane aviation fuel the plane ran and at atmospheric pressures lower than see level the water atomized (broke down to hydrogen and oxygen and added power!!!) just like the nitrous oxide adds extra hydrogen and oxygen to make more power. Its draw back was it increased the thermal output of combustion and could melt the pistons. I will talk to the Allison mechanic that goes to my church who worked on these systems and conform my facts.

Highly unlikely the hydrogen and oxygen separate in the combustion chamber. Water is a by-product OF the combustion process - the chemical bond is extremely strong. The energy required to separate the two would not result in a more energetic reaction anyway - you are not starting from a higher energy state.

[Scottie-GNZ]

As BLKMGK stated, alcohol/water is very popular among the Buick turbo crowd. It is not a crutch but an alternative to running high boost w/o race gas because of the cost of race gas and O2 contamination. BLKMGK is also correct in that it does not make as much HP as race gas. It is not uncommon for a turbo Buick limited to 15-16psi boost on the street with 93-octane to run 23-24psi with the alcohol injection.

[Guest shuyun]

Looks like the power boost comes form the Methanol-Water mixture not just a Water addition just one example I came across.

 

From:

http://www.nasm.si.edu/nasm/aero/aircraft/focke_ta152.htm

 

Kurt Tank chose the same workhorse Jumo 213 powerplant used in the Fw 190D. For the Ta 152H, he selected an uprated version, the Jumo 213E, equipped with a 2-stage, 3-speed mechanical supercharger and MW 50 engine boost. The MW 50 system used methanol-water mixture to boost engine output from 1,312 kw (1,750 hp) to 1,537 kw (2,050 hp) for short periods

[Pop N Wood]

shuyun

 

Excellent post. I have seen that aircraft up close at the NASM's Garber facility here in Maryland. I didn't realize it was so rare.

 

But don't read too much into what was written. The water methonal injection by itself does nothing. But kicking in the WM injection allows you to increase boost/timing/etc for max HP.

 

Also I am not sure what adding methonal to the water does for HP. On a high altitude interceptor it would be essential as an antifreeze.

 

I would like to know how they adjusted boost on those engines. Maybe they had some type of adjustable waste gate? Note that the article said those engines had multi speed superchargers. But I know on the Spitfires they switched supercharger "gears" (speeds) as they went up and down in altitude to compensate for different air densities. In fact, the Spitfires actually had different models that had engines optimized for combat at different altitudes. One variant had supercharger shift points dialed in for high altitude interception of bombers, whereas different variants worked best at meduim to low altitude.

[A. G. Olphart]

The last water injection I've dealt with was on a John Deere 'D', and it did away with the ping under load with distillate fuel. (Actually, on the 'D' it was more of a clang than a ping).

 

Fast forward a few decades:

 

Does anyone have a recipe for putting a fogger under my Holley?

 

Adjusting water flow for engine rpm and throttle opening would seem to be a bit of a trick for non computer/ non injected engines. Need any other variables be considered?

[Guest Anonymous]

I always learn something from you wise ones , repeat lone, water injection is not a crutch... oh well I'm used to tasting my own foot.. my bad...

I know it'd be expensive, but how about a small fuel cell of race gas to fire extra injectors with (say 3-5 gals)? I know it'd cost out the butt, but if your not in it all the time, it's just waiting there? I know the alcohol mix would be cheaper by far though, just thinking out loud, thanks for the lesson.

 

Regards,

 

Lone

 

Ps: Ahem, sorry just saw the 02 contamination, jeez, forget it, jedi mind trick, 'I never posted on this topic, they are not the droids your looking for'

[TimZ]

Yes, water injection has been known to be effective for years.

 

This is all well and good at the track, and it's perfectly acceptable to use it there. On the street, you'd best pray that you don't run out of water. That race gas will start looking pretty cheap about then...

 

This is the biggest reason that you don't see water injection on more applications - it's not a robust system, and it's failure modes are pretty catastrophic. Period.

 

A couple of other points...

 

Water has a much higher specific heat than alcohol, which means that the alcohol actually reduces the amount of heat gets taken out of the system. As was mentioned, the alcohol is generally required to keep the water from freezing.

 

Now I've seen some claims about the water-alcohol mix making more power, too. This I don't have a good explanation for, although there are many variables that could be responsible for this.

 

Assuming that the engine had proper fuel delivery and a stoich or richer mixture to begin with, there should not be any oxygen left over to burn the alcohol, so it should not give an increase in power over pure water.

 

If the mixture was lean to begin with, then this might explain the power increase with alcohol added. Sorry guys, but this particular case smells like a crutch to me - and a dangerous one at that.

[Guest pvtkary]

when the water asorbs thermal energy from the combustion process to do a phase change. the water will increase its volume roughly 220 times. I think that that is the number I dont have a thermodynamics text handy. Any way this is where some of the power comes from.

[Kevin Shasteen]

Highly unlikely the hydrogen and oxygen separate in the combustion chamber. Water is a by-product OF the combustion process - the chemical bond is extremely strong. The energy required to separate the two would not result in a more energetic reaction anyway - you are not starting from a higher energy state.[/QB]

Suppose there were a Catalyst that cracked the fuel molecule prior to the combustion chamber-as in "TCC"...Thermal Catalytic Cracking?

 

Mostly over my head-but the writer basically said that a fuel molecule could be cracked if it came in to contact with a Catalyst and the fuel was under pressure prior to the Catalyst.

 

What would you use it for-well, the more astute would have to answer that question; as I said-that is mostly over my head stuff but the writer did say when the fuel molecule was cracked what was left over was water & hydrogen.

 

Kevin,

(Yea,Still an Inliner)

[Guest pvtkary]

wow this guy who wrote about cracking must have a space ship in his back yard or something. what happened to the carbon. Fusion? Fishon? Cracking is done during the distlation process using ethelilene as a catalist, and some heat, and pressure. This cracks appart the larger hydrocarbon chains into smaller more volatle chains. basically yielding some more sweet fractions out of the left over heavier molocules.

[Sparky]

hey fellas,

 

ive been day dreaming about this kind of setup for a while....doing research on what parts to use...cost..controling such a system ETC. Ive got 90% of my system figured out...its the last 10% thats bothering me.

 

ive found a fully programable AIC its basicaly a relay box controlled by a MAP sensor. it just triggers relays at a given (laptop programmable) point. I will be using this black box to control the fuel pump as well as a NOS solenoid. the fuel pump will turn on at X PSIboost followed by the activation of the solenoid at X+3-5 PSIboost. im still up in the air as to what to inject ( alcohol, methonol, ethanol, toulene(sp?)) etc.

 

but my main problem is...where should i inject the mix. should i use one or two fogger nozzles before the TB...or should i have six fogger nozzles as close to the head as possible. My thinking is to bite the bullit...pull out "YE OLE CREDITCARD" at buy six fogger nozzles. with the duel inlets...i use one for substance X and the other for fuel...or maybe another substance X.

two small tanks...on with a 50/50 wateralchy mix and another with race gas? perhaps? this is the 10% im not sure of...i know all the parts i need...and where to put most of them...but what to inject...and where in the system is still up in the air. im not concerned about the cost...so its not a factor when chosing one-or six. i just want to know what would be better.

 

eventually i will anty up and but a nice EMS. but when i get and idea in my head for something i want to do...even if i could spend a little bit more for something better...i have to see it through. my ex called me stubborn...comes to think of it...everyone calls me stubborn.

 

anywho...love to hear the oppinons of the hybrid crew. yall are always my biggest source of info.